Convert a pointZ layer to a point layer

Ditching the Z: How to Turn a PointZ Layer into a Regular Point Layer

Ever worked with maps and data where you had points scattered all over, each marking a specific location? That’s the world of Geographic Information Systems (GIS) in a nutshell. Now, sometimes these points are just that – points on a map. But other times, they come with extra baggage: elevation data. That’s when you’re dealing with a PointZ layer. Think of it like this: a regular point layer tells you where something is, while a PointZ layer tells you where and how high it is.

While that extra “Z” (for altitude) can be super useful, especially if you’re doing anything with 3D visualizations or terrain analysis, it can also be a pain. I’ve been there myself, trying to run a simple analysis only to be met with errors because the software couldn’t handle the Z-dimension. Or worse, dealing with massive files that take forever to process, all because of that extra elevation data. Sometimes, you just need those good old 2D points. So, how do you ditch the Z? Let’s dive in.

PointZ Layers: What’s the Deal?

Okay, let’s break it down. A regular point layer is simple: it’s got an X and a Y coordinate, telling you exactly where something is on a flat surface. A PointZ layer, though, adds a third dimension: the Z-value. This usually represents elevation – how high above sea level that point is.

Now, why would you want to get rid of this extra data? Well, for starters, not all GIS tools play nice with PointZ layers. You might run into compatibility issues or just find that the software chugs along at a snail’s pace. Plus, all that extra Z-data bloats your file size, making everything slower.

Z-Be-Gone: Converting PointZ Layers

The good news is, converting a PointZ layer to a regular point layer isn’t rocket science. The exact steps depend on which GIS software you’re using, but here are a few common methods:

QGIS to the Rescue

QGIS, being the awesome open-source tool it is, makes this pretty straightforward:

• “Save As” is Your Friend: This is probably the easiest way. Just right-click on your PointZ layer, choose “Save As,” and then, under “Geometry Type,” pick “Point.” The crucial part? Make sure you uncheck that little box that says “Include Z-dimension.” Boom! New point layer, Z-free.
• Get Expressive with Geometry: QGIS also lets you use expressions to manipulate your data. Head to the “Geometry by Expression” tool, and use this little snippet of code: make_point(x($geometry), y($geometry)). What this does is create a new point using only the X and Y coordinates, effectively ignoring the Z-value.

ArcGIS Pro: The Pro Approach

If you’re rocking ArcGIS Pro, Esri’s powerful desktop GIS software, you’ve got a few options too:

• Feature Class to Feature Class: This tool is a workhorse for converting data. Just point it at your PointZ layer, tell it you want a regular point layer, and ArcGIS Pro will automatically drop the Z-dimension. Just double-check your environment settings to make sure “Output has Z values” is turned off, just to be safe.
• Copy That Feature: Similar to the “Feature Class to Feature Class” tool, “Copy Features” can also strip away that Z-dimension.
• Table Export and XY Display: This is a bit of a workaround, but it works. First, add X and Y fields to your PointZ layer and calculate their values. Then, export the whole thing as a table, and use the “Display XY Data” tool to create a brand-new point layer.

PostGIS Power

If you’re a database whiz using PostGIS, you can use the ST_MakePoint function in an SQL query. This lets you create a new table with 2D points derived from your PointZ data.

A Few Things to Keep in Mind

Before you go Z-deleting crazy, here are a few things to consider:

• Z is Gone Forever: Once you convert, that Z-data is gone. Make sure you don’t need it for anything else!
• Attributes Should Tag Along: Usually, all the other information attached to your points (like names, IDs, etc.) will come along for the ride. But it’s always a good idea to double-check.
• Software Quirks: Every GIS program is a little different, so the exact steps might vary. Check your software’s help documentation if you get stuck.

Final Thoughts

Converting PointZ layers to regular point layers is a pretty common task in the GIS world. Whether you’re trying to improve performance, ensure compatibility, or just simplify your data, knowing how to ditch the Z is a valuable skill. Just remember to think about whether you really need that elevation data before you delete it! Trust me, I’ve learned that lesson the hard way. Now go forth and map!